JP2005282735A - Bound stopper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bound stopper, in which a restraining ring is installed on an outer circumferential surface of a cylindrical stopper main body formed of elastic material, in such structure that cracking or damages are not generated in the elastic material forming the stopper main body that is deformed as a load is inputted. <P>SOLUTION: This bound stopper comprises the restraining ring 14 formed to have a roughly rectangular cross sectional surface with rigidity, so that it is engaged with/locked to a recessed groove 18 formed in an outer circumferential surface at an axial middle part of the cylindrical stopper main body. Inner circumferential side angular parts 20 and 20 of the restraining ring 14 are cut off to form closed cavities 22 and 22 extended in the circumferential direction of the recessed groove 18 and the restraining ring 14 between contact surfaces of the stopper main body 12 and the restraining ring 14 to each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bounce stopper that is extrapolated to a piston rod of a shock absorber and elastically limits an operating stroke of the shock absorber, and more particularly, a bounce in which a rigid restraining ring is fitted to an outer peripheral surface thereof. It relates to the stopper.

  Conventionally, shock absorbers that make up vehicle suspensions have been provided with a cylindrical bounce stopper formed by an elastic body such as rubber or urethane, which is externally attached to the piston rod. In some cases, the bound stopper is compressed and deformed in the axial direction between the shock absorber cylinder and the vehicle body side or wheel side member to which the piston rod of the shock absorber is attached. It is limited elastically.

  Such a bound stopper requires a non-linear spring characteristic that is soft when the shock absorber operating stroke is small and sufficiently hard when the shock absorber is large in order to achieve both good riding comfort and steering stability. In addition, it is required to ensure a sufficiently large operating stroke of the shock absorber while preventing interference with other members such as a dust cover.

  By the way, as such a bound stopper, for example, in Japanese Utility Model Publication No. Sho 62-11006 (Patent Document 1), a straight upper cylinder with a large pressure-receiving area located on the suspension insulator side. And a lower cylindrical portion located on the cylinder side of the shock absorber, the outer diameter of which is reduced toward the lower side, the pressure receiving area is reduced, and the lower end portion is bent in a bellows shape. While having an elastic cylindrical body made of urethane foam, an annular groove extending in the circumferential direction is formed on the outer peripheral surface of the boundary between the lower cylindrical portion and the upper cylindrical portion of the elastic cylindrical body, and the annular groove has a predetermined rigidity. A vehicle suspension bumper spring is shown which is configured by fitting and mounting the ring.

  In Japanese Patent No. 3214435 (Patent Document 2), an elastic material such as foamed urethane rubber is used in which one end is fixed to the vehicle body side and the other end is a free end. The cylindrical stopper body is formed in a ring shape on a part of the outer periphery of the bellows-shaped expansion / contraction part of the cylindrical stopper body, and its cross-sectional shape is from the action start side that receives the impact external force by the contact of the damper. Therefore, the side facing the free end of the expansion / contraction part is set to the minimum inner diameter of the maximum wall thickness, while the side facing the fixed end is set to the maximum inner diameter of the minimum wall thickness, and the inner peripheral surface is tapered so as to gradually increase in diameter. Thus, a bump stopper has been clarified in which the constraining ring is fitted and held.

  Then, according to the bound stopper such as the bumper spring for vehicle suspension or the bump stopper, when the load is input to the bound stopper, the restraining ring having the rigidity engaged with the outer peripheral surface thereof is used. Deformation such that the part of the swelled bulges outward in the radial direction is effectively suppressed, and the deformation of the stopper body at the time of heavy load input is limited, realizing a hard spring characteristic In addition to preventing interference with other members due to the outward bulging of the bound stopper, the deformation stroke of the bound stopper main body is increased to achieve low spring characteristics when a small load is input. It has become.

  However, in the bound stopper having such a configuration, the outer peripheral surface of the stopper main body and the surface in contact with the restraining ring are fitted so as to closely contact each other. As shown in FIG. 2, when the bound stopper is compressed and deformed by load input, the portion of the stopper body between the portion where the restraining ring is fitted and the damper (absorber plate) (in FIG. 2) The elastic expansion / contraction part 15) is compressed between the restraining ring and the damper (absorber plate), and expands to the outside in the radial direction more than the outer diameter of the restraining ring and the outer diameter of the upper surface of the damper. Therefore, such a bulging portion comes into contact with the end portion (edge) of the restraining ring or the damper (absorber plate), and as a result, the stopper The elastic body constituting the body, there is a possibility that cracking or damage, etc. may occur.

Japanese Utility Model Publication No. 62-11006 Japanese Patent No. 3214435

  Here, the present invention has been made in the background of such circumstances, and the problem to be solved is to attach a restraining ring to the outer peripheral surface of a cylindrical stopper body formed of an elastic body. It is an object of the present invention to provide a bound stopper structure that does not cause a crack or the like in an elastic body constituting a stopper body that is deformed by a load input.

  And, in the present invention, in order to solve such a technical problem, a bound stopper is provided that is extrapolated to the piston rod of the shock absorber and elastically limits the operating stroke of the shock absorber. While having a cylindrical stopper body formed of an elastic body, a concave groove having a rectangular cross-sectional shape extending in the circumferential direction is formed on the outer peripheral surface of the axially intermediate portion of the stopper main body, while in the concave groove, A rigid restraint ring having a substantially rectangular cross section is fitted and locked, and the inner peripheral surface of the restraint ring and both end surfaces in the axial direction with respect to the bottom surface and both side surfaces of the concave groove And a space extending in the circumferential direction of the concave groove and the constraining ring is formed between the contact surfaces of the concave groove and the constraining ring. bound The stopper is for its gist.

  Further, according to one of the preferred embodiments of the bound stopper according to the present invention for solving such a problem, the outer diameter of the restraining ring is larger than the outer diameter of the absorber plate of the shock absorber that is brought into contact with the stopper body. It will be constituted.

  Furthermore, in another aspect according to the present invention, at least one corner on the inner peripheral side of the restraining ring is cut off, and the space is formed between the bottom corner of the concave groove. The bouncing stopper formed in the circumferential direction is also a feature.

  Furthermore, according to one of the other desirable embodiments of the bound stopper according to the present invention, a circumferential groove extending in the circumferential direction of the restraining ring is formed on an end face of the shock absorber in the axial direction of the restraining ring. When the circumferential groove is formed and covered with the side surface of the concave groove, the space is formed in the circumferential direction.

  Thus, in the bound stopper according to the present invention, the transverse section has a substantially rectangular shape in the concave groove formed in the outer peripheral surface of the axially intermediate portion of the cylindrical stopper body formed of an elastic body. The part where the restraint ring of the stopper main body is locked when the bound stopper is compressed and deformed by the load input from the place where the rigid restraint ring is engaged and locked. Since the deformation to the outside in the radial direction is restricted, the portion of the stopper body where the restraint ring is fitted and the other portion will exhibit different spring characteristics, As a result, a non-linear spring characteristic is exhibited.

  And there is a space extending in the circumferential direction of the concave groove and the restraining ring between the contact surface of the concave groove formed on the outer peripheral surface of the stopper body and the restraining ring having a substantially rectangular cross section. When the stopper body of the bound stopper is compressed and deformed by the load input, the elastic body constituting the stopper body compressed between the restraining ring and the absorber plate is restrained from the concave grooves. As a result, the elastic body that has been compressed and deformed is deformed so as to swell larger than the outer diameter of the absorber plate or the restraining ring. Without contact, it is possible to advantageously avoid contact between the elastic body and the end face (edge) of the absorber plate or the restraining ring. Risk of cracking or damage occurs in the elastic body constituting the path body, it is becoming an be effectively eliminated.

  In one of the desirable embodiments of the bound stopper according to the present invention, the outer diameter of the restraining ring is larger than the outer diameter of the absorber plate of the shock absorber that is brought into contact with the stopper body. However, in such a structure, the corners of the absorber plate come into contact with the elastic body portion of the stopper body which is compressed between the restraining ring and the absorber plate and bulges, causing damage. In other words, these problems can be solved more effectively by adopting the present invention.

  Further, according to one of the other preferred embodiments of the bound stopper according to the present invention, at least one corner on the inner peripheral side of the restraining ring is cut off, and the bottom corner of the concave groove and the restraining ring are In the meantime, since the predetermined space is formed in the circumferential direction, it is not necessary to form the restraining ring with a special shape in order to form such a space. It can be improved.

  Furthermore, according to one of the other desirable embodiments of the bound stopper according to the present invention described above, the shock absorber is located on the side of the absorber plate when fitted into the concave groove of the stopper body on the axial end surface of the restraining ring. Since the circumferential groove extending in the circumferential direction of the restraining ring is formed on the end face to be, and a predetermined space is formed in the circumferential direction on the side surface of the circumferential groove and the concave groove, It is possible to advantageously secure a space for accommodating an elastic body that is compressed and deformed between the restraining ring and the absorber plate and bulges outward in the radial direction of the restraining ring.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 shows a bound stopper 10 according to the present invention in a longitudinal section. As is clear from this figure, the bound stopper 10 is provided with an insertion hole 16 extending through the central axis thereof, and a groove 18 extending in the circumferential direction is formed on the outer peripheral surface of the axially intermediate portion. The stopper main body 12 has a substantially cylindrical shape as a whole, and the constraining ring 14 having a substantially rectangular shape in cross section, which is fitted in and engaged with the concave groove 18.

  More specifically, the stopper body 12 includes an upper cylindrical portion 24 having a thick cylindrical shape, a lower cylindrical portion 28 having a thin cylindrical shape bent in a bellows shape, and the upper cylindrical portion 24 and the lower cylindrical portion. It is comprised from the intermediate | middle cylindrical part 26 which is located between the parts 28 and exhibits the cylindrical shape of a medium thickness. And it opens to an outer peripheral surface with a substantially V-shaped cross-sectional form so that it may be located in each boundary part of such upper cylindrical part 24 and middle cylindrical part 26, and middle cylindrical part 26 and lower cylindrical part 28, The straight portions 30 and 32 continuously extending in the circumferential direction are formed, and the outer peripheral surface of the axial end portion of the lower cylindrical portion 28 is formed as a tapered tapered surface 34.

  Further, the outer peripheral surface of the intermediate cylindrical portion 26 of the stopper main body 12 has a substantially rectangular cross-sectional shape as shown in the partial enlarged views of FIGS. 1 and 2, and an annular shape that extends continuously in the circumferential direction. A concave groove 18 is formed. The outer peripheral surface of the stopper main body 12 is formed into a bent substantially bellows shape by the concave grooves 18, the above-described straight portions 30 and 32, and the tapered surface 34. Further, the axial end surface of the upper cylindrical portion 24 of the stopper main body 12 has a radial direction that functions as an air vent passage for the insertion hole 16 covered with the suspension insulator 44 and the absorber plate 48 when assembled to the shock absorber 40. A groove 36 is formed. Such a stopper main body 12 is formed of various known rubbers and elastic bodies such as urethane. In the present embodiment, the stopper main body 12 is formed by using foamed urethane rubber, so that it is soft. Spring characteristics can be demonstrated.

  On the other hand, the restraining ring 14 is made of a material having rigidity such as metal or resin, has a substantially rectangular cross section, and has an inner diameter and thickness corresponding to the concave groove 18 of the stopper body 12. Further, as is clear from FIGS. 1 and 2, the corners 20, 20 on the inner peripheral side are cut out and formed as R surfaces that draw a gentle curved surface, respectively. . In the present embodiment, the outer diameter of the restraining ring 14 is configured to be larger than the outer diameter of the absorber plate 48 of the shock absorber 40 to which the bound stopper 10 is assembled as shown in FIG. ing.

  Then, such a restraining ring 14 is fitted into the concave groove 18 of the stopper main body 12 and locked, whereby the bound stopper 10 is formed. At that time, each side surface of the concave groove 18 and both end surfaces in the axial direction and the inner peripheral surface of the constraining ring 14 come into contact with each other, and the constraining ring 14 is locked in the concave groove 18. However, in the corners 20 and 20 cut into a curved shape on the inner peripheral side of the restraining ring 14, between the corners 20 and 20 of the restraining ring 14 and the respective bottom corners of the corresponding concave groove 18, The cavities 22 and 22 closed from the outside are formed so as to continuously extend in the circumferential direction.

  By the way, the bound stopper 10 formed in this way is externally attached to the piston rod 42 of the shock absorber 40 in the insertion hole 16 of the stopper main body 12 as shown in FIGS. 3 and 4, for example. 42 is disposed between the suspension insulator 44 for supporting the vibration isolation on the vehicle body side and the cylinder 46 of the shock absorber 40, so that when the shock absorber 40 is contracted by a load input, the suspension insulator 44 and the upper surface of the cylinder 46 are disposed. It is compressed and deformed in the axial direction between the absorber plate 48 and the operating stroke of the shock absorber 40 is elastically limited.

  As described above, in the bound stopper 10 having such a structure, when a small load is input, the portion formed in the bellows shape of the lower cylindrical portion 28 of the stopper main body 12 is elastically deformed mainly in the shearing direction. In addition, the soft spring characteristic can be advantageously exerted, and as the load gradually increases, the lower cylindrical portion 28 is crushed in the axial direction, and the straight portion 32 that is open on the outer peripheral surface is closed, and the lower portion The cylindrical portion 28 is compressed and deformed, and the upper cylindrical portion 24 is elastically deformed from the intermediate cylindrical portion 26. In this case, since the intermediate cylindrical portion 26 is restricted from bulging outward by the restraining ring 14, when the deformation amount is relatively small, a soft spring characteristic is exhibited, and the deformation amount increases. The spring characteristic that hardens suddenly is more effectively exhibited. As described above, since the non-linear spring characteristics can be exhibited as the entire bound stopper 10, good riding comfort and steering stability of the vehicle are highly compatible.

  Here, as shown in FIG. 4, the elastic body which is compressed and deformed between the restraining ring 14 and the absorber plate 48 in the stopper body 12 which is compressed and deformed by a large load input is restrained with the stopper body 12. Since it is deformed so as to fill the voids 22 formed between the ring 14 and the ring 14, it is compressed between the restraining ring 14 and the absorber plate 48 like a conventional bound stopper. The problem that the elastic body that gives the intermediate cylindrical portion 26 and the lower cylindrical portion 28 bulges outward larger than the outer diameter of the restraining ring 14 and the absorber plate 48 can be effectively eliminated. The elastic body constituting the stopper main body 12 is in contact with the restraint ring 14 or the end (edge) of the absorber plate 48. Averted obtained, as a result, the elastic body of the stopper main body 12, a possibility that a crack or the like or generation is than the be effectively eliminated.

  Further, in the bound stopper 10, the circumferential space 22 formed between the contact surfaces of the restraining ring 14 and the groove 18 is formed as a space closed from the outside, so that the space from the outside is formed. The function of the space can be advantageously maintained by preventing foreign matters from entering. In particular, the bound stopper 10 is always close to the tire since it is used by being externally attached to the piston rod 42 of the shock absorber 40. Therefore, foreign matters such as mud and dust from the ground are easily attached, and This is because, when the space is filled by the adhesion, the characteristics cannot be effectively exhibited.

  As mentioned above, although one typical embodiment of the present invention has been described in detail, it is merely an example, and the present invention is interpreted in a limited manner by a specific description in such an embodiment. It should be understood that this is not the case.

  For example, in the above-described embodiment, the corners 20 and 20 on the inner peripheral side of the restraining ring 14 are cut out so as to draw a gentle curved surface, and are formed into an R surface. Although the voids 22 and 22 were formed, as shown in FIG. 5A, flat cut surfaces (C surface) 50 and 50 are formed as such cut surfaces 50 and 50 and the groove 18. A space 52, 52, which is a closed space, may be formed between them. Further, as shown in FIG. 5B, a circumferential direction is formed on the end surface of the restraining ring 14 in the axial direction on the absorber plate side. It is also possible to form a void 56 between the side surface of the recessed groove 18 by forming a circumferential groove 54 extending in the direction of the groove.

  Further, in the structure of the bound stopper 10 shown in FIG. 1, both corners 20, 20 on the inner peripheral side of the restraining ring 14 are respectively cut off on the R surface to form two cavities 22, 22. However, it is also possible to form a void 22 at one of the corners 20, and in that case, the corner on the absorber plate side (lower side in FIG. 1) of the shock absorber. It is desirable that the space 20 be provided in the part 20. In the case where one void is provided at the corner of the restraining ring as described above, the same applies to the embodiment shown in FIG. Furthermore, even when the circumferential groove 54 is provided on the axial end face of the restraining ring 14, not only one end face side as shown in FIG. 5B but also the other end face side (FIG. 5B It is also possible to provide a similar circumferential groove (54) also on the upper surface side of the constraining ring 14 in FIG.

  Further, the illustrated cavities 22, 52, 56 as spaces extending in the circumferential direction of the restraining ring 14 and the recessed groove 18 are all formed in a form closed from the outside. In addition, the circumferentially extending space is formed on the inner surface of the groove 18 with or instead of the illustrated processing for the restraining ring 14. It is also possible to form a circumferential groove between the constraining ring 14.

  In the stopper main body 12, it is not always necessary to provide the straight portions 30, 32, and when forming such a straight portion, the cross section exemplified in the present embodiment is not limited to the V-shaped cross section. Of course, it is also possible to use a straight portion having a cross-sectional shape such as a letter shape. Further, the number of strips disposed on the straight portion may be increased or decreased according to desired spring characteristics and the like.

  Further, the specific shape of the stopper main body 12 is not limited to that of the illustrated embodiment. For example, the stopper main body 12 has a bellows shape over the entire length in the axial direction, or a straight tube having no bellows-like portion. It can also be in the form of a body.

  In addition, although not listed one by one, the present invention can be implemented in a mode with various changes, modifications, improvements, and the like based on the knowledge of those skilled in the art. It goes without saying that any one of them falls within the scope of the present invention without departing from the spirit of the invention.

It is longitudinal cross-sectional explanatory drawing which shows an example of the bound stopper according to this invention. FIG. 2 is an explanatory cross-sectional view showing, in an enlarged manner, a fitting portion of the bounding ring into the concave groove of the bound stopper shown in FIG. FIG. 2 is an explanatory cross-sectional view showing an example of a state where the bound stopper shown in FIG. 1 is assembled to a shock absorber. FIG. 4 is an explanatory cross-sectional view showing a compressed state of the bound stopper shown in FIG. 3. It is sectional explanatory drawing which expands and shows the fitting part to the ditch | groove of a restraint ring about another example of the bound stopper according to this invention, Comprising: (a) is a corner | angular part of the inner peripheral side of a restraint ring planar (B) shows that a circumferential groove extending in the circumferential direction is formed on one axial end face of the restraining ring.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Bound stopper 12 Stopper main body 14 Restraint ring 16 Insertion hole 18 Concave groove 20 Corner part 22 Space

Claims (4)

The bounce stopper that is extrapolated to the piston rod of the shock absorber and elastically limits the operating stroke of the shock absorber,
While having a cylindrical stopper body formed of an elastic body, a concave groove having a rectangular cross-sectional shape extending in the circumferential direction is formed on the outer peripheral surface of the axially intermediate portion of the stopper main body, while in the concave groove, A rigid restraint ring having a substantially rectangular cross section is fitted and locked, and the inner peripheral surface of the restraint ring and both end surfaces in the axial direction with respect to the bottom surface and both side surfaces of the concave groove And a space extending in the circumferential direction of the concave groove and the restraining ring is formed between the contact surfaces of the concave groove and the restraining ring. Bound stopper.   The bound stopper according to claim 1, wherein the restraining ring has an outer diameter larger than an outer diameter of an absorber plate of the shock absorber that is brought into contact with the stopper main body.   3. The space according to claim 1, wherein at least one corner on the inner peripheral side of the restraining ring is cut off and the space is formed in the circumferential direction between the bottom corner of the concave groove. The bound stopper described. A circumferential groove extending in the circumferential direction of the restraining ring is formed on an end face of the shock absorber in the axial direction of the restraining ring, and the circumferential groove is covered with a side surface of the concave groove, thereby The bound stopper according to any one of claims 1 to 3, wherein the space is formed in a circumferential direction.

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